Fuel cell power supply

Abstract

A fuel cell power supply including a fuel cell and a secondary cell comprises a fuel cell current detector for detecting the fuel cell current generated by the fuel cell; a load current detector for detecting a load current flowing through the load of the fuel cell power supply and for producing a load signal corresponding to the load current; a setting device for producing a set signal corresponding to the strength and time variation pattern of the output signal; and a control device for receiving the output signal and the set signal and for controlling the strength of the fuel cell current.

What is claimed is: 
     
       1. A fuel cell power supply including a fuel cell and a secondary cell for backing up the fuel cell, comprising: fuel cell current detecting means for detecting the fuel cell current generated by the fuel cell; load current detecting means for detecting a load current flowing through the load of the fuel cell power supply and for producing a load signal corresponding to the load current; setting means for producing a set signal corresponding to the strength and time variation pattern of the output signal of the load current detecting means; and control means for receiving the output signal of the fuel cell current detecting means and the set signal of the setting means and controlling the strength of the fuel cell current. 
     
     
       2. A fuel cell power supply as claimed in claim 1, wherein said setting means includes means for correlating the output signal of the load current detecting means to an intermittent overload current, and the control means includes means for converting the fuel cell current into overcurrent having a value greater than the rated output current of the fuel cell and a value corresponding to the interval of the intermittent overload current. 
     
     
       3. A fuel cell power supply including a fuel cell and a secondary cell for backing up the fuel cell, comprising: fuel cell current detecting means for detecting the fuel cell current generated by the fuel cell; load current detecting means for detecting a load current flowing through the load of the fuel cell power supply and for producing a detection signal corresponding to the load current; setting means for receiving the detection signal, said setting means for producing a first set signal free from variation with time when the value of the detection signal does not exceed a fixed value, and for producing the combination of the first set signal and a second set signal proportional to the value of the first detection signal and added to the first set signal for a period corresponding to the value of the first detection signal when the first detection signal exceeds the fixed value; and control means for receiving the output signal of the fuel cell current detecting means and the set signal of the setting means and for controlling the strength of the fuel cell current.